1. Field of the Invention
The present invention relates to an image recording apparatus for recording an image on an image recording medium, and more particularly to an image recording apparatus which develops by coating a developer on a photosensitive recording medium on which the latent image is formed based on information about an image.
2. Description of Related Art
Conventionally, an image recording apparatus for recording an image on a recording medium with a capsule sheet (photosensitive recording medium) having microcapsules as described in the U.S. Pat. No. 4,399,209 is used. Each of the microcapsules encapsulates therein a chromogenic material and a photosensitive material which changes mechanical strength according to the amount of the irradiated light to which it is exposed.
One of the above mentioned image recording apparatuses is disclosed in Japanese Pat. Application No. 2-33260.
First, the structure of the image recording apparatus and operation for recording an image will be described with reference to FIG. 4.
An operator opens an original support stand glass cover 102a mounted on the image recording apparatus and puts an original 103 on a support stand glass 102 facing down. The operator then places the original support stand glass cover 102a on the original 103. Next, when the operator presses a start switch (not shown), an exposure lamp 101 is lit, and an image recording operation is started. The light emitted from the exposure lamp 101 irradiates the original 103 placed on the original support stand glass 102, and the light is reflected by the original 103. The light reflected by the original 103 carries information about an image. The reflected light irradiates a capsule sheet 105 supplied from a cartridge 104 and is focused on the capsule sheet 105 through a lens. The capsule sheet 105 has a conductive substrate on which numerous microcapsules are coated. When the reflected light irradiates the microcapsule side of the capsule sheet 105, a latent image of the original image is formed on the microcapsule side. At this time, the original support stand glass 102 on which the original is placed is moved by a drive source (not shown). The capsule sheet 105 moves in synchronization with the movement of the original support stand glass 120. The latent image of the original image is thus formed on the microcapsule side of the capsule sheet 105. An unused capsule sheet 105 is stored on a capsule sheet roll 106 in the cartridge 104 and a used capsule sheet 105 is taken up by a take up roll 112 in the cartridge 104 through guide rollers 107, 108, 109, 110, 111 and a development roller 118b. As A.C. power is connected to the take up roller 112, a voltage can be applied to a substrate of the capsule sheet 105. When developer particles 115 come in contact with a chromogenic material involved in the microcapsules, the developer particles 115 react on the chromogenic material and are colored.
A developer coating unit 113 comprises a case 114, a charging roller 116 and a carrying roller 117. The developer particles 115 are stored in the case 114. As the charging roller 116 comes in contact with the developer particles 115 and causes friction, the developer particles 115 become charged. The carrying roller 117 transmits the developer particles 115 to come in contact with the capsule sheet 105 by rotation of the carrying roller 117 having the charged developer particles 115 on its surface. When the capsule sheet 105 on whose microcapsule side the latent image of the original image is formed by the light reflected by the original 103 passes the front of a developer coating unit 113, the developer particles 115 are drawn electrostatically to the latent image from the carrying roller 117. As the take up roll 112 is connected to the A.C. power supply, the substrate of the capsule sheet 105 can be applied a voltage.
The capsule sheet 105 forming the latent image coated by the developer particles 115 is carried to a pressure development unit 118. Just before the capsule sheet 105 forming the latent image is introduced into the pressure development unit 118, the latent image portion of the capsule sheet 105 is superposed with ordinary paper 119 delivered from a cassette 122. The capsule sheet 105 and the ordinary paper 119 are introduced into the pressure development unit 118 together, and they are sandwiched and pressed together between development rollers 118a and 118b. At this time, microcapsules which are hardened by receiving the reflected light are not ruptured under the pressure, while the microcapsules which are not hardened by the reflected light are ruptured under the pressure. As chromogenic material flows from the ruptured microcapsules, the chromogenic material comes in contact with the developer particles 115 and reacts with them to cause coloring. Accordingly, a recording image is formed on the ordinary paper 119 corresponding to the original image. Afterwards, the ordinary paper 119 is separated from the capsule sheet 105 by the guide roller 109 and the capsule sheet 105 is taken up by the take up roll 112. On the other hand, after the ordinary paper 119 on which the recording image has been formed is separated from the capsule sheet 105, the ordinary paper 119 is heated and fixed by a fixing unit 120 for fixing the recording image on the ordinary paper 119. The ordinary paper 119 on which the recording image has been fixed is discharged through an outlet 121 to the exterior of the image recording apparatus and is finally laid on the discharge tray 123.
According to the above mentioned image recording apparatus, if the image recording operation is executed many times and the entire capsule sheet 105 is taken up by the take up roll 112, the capsule sheet 105 is used up. When the capsule sheet 105 is used up, the operator opens a maintenance panel (not shown) provided on the upper side of the exterior of the image recording apparatus and exchanges the used cartridge 104 for a new cartridge 104 to store an unused capsule sheet 105. Moreover, when the entire capsule sheet 105 is taken up by the take up roll 12 in the cartridge 104 and is thus used up, the developer particles 115 in the developer coating unit 113 are almost used up as a result of being coated to the capsule sheet 105. Therefore, the operator also has to exchange the empty developer coating unit 113 for a new developer coating unit 113 to store the developer particles 115. Accordingly, the operator has to open the maintenance panel and exchange both the cartridge 104 and the developer coating unit 113 for a new cartridge 104 and a new developer coating unit 113, respectively, since the capsule sheet 105 and the developer particles 115 are used up almost at the same time. Therefore, the exchanging operation is troublesome.
Moreover, because the cartridge 104 and the developer coating unit 113 are separately provided in the image recording apparatus, this image recording apparatus must be large in size.